Difficulty installing postgresql on Max OSX Leopard.

I'm working with an open source Electronic Medical Record application
'GNUmed" which uses postgresql. I've had a difficult time installing
version 8.4.1 from source code on my Mac.

The best set of instruction i've found is from http://zanshin.net/2009/09/07/installing-postgresql-on-mac-10-6-snow-leopard/
, however it did not quite do the trick. Going by the instructions
there:

> On starting the server:
>
> bash-3.2$ /usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data/ -l
> server.log start
> zanshin.net » Installing PostgreSQL on Mac 10.6 (Snow Leopard) »
> Blog Archive server starting
>
> If I use this command to stop server I get:
>
> /usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsqsl/data/ -l server.log
> stop
> pg_ctl: PID file "/usr/local/pgsqsl/data/postmaster.pid" does not
> exist
> Is server running?

> Creating the db:
> bash-3.2$ createdb testdb
> createdb: could not connect to database postgres: could not
> connect to server: No such file or directory
> Is the server running locally and accepting
> connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

> The server.log entries:
> postgres cannot access the server configuration file "/usr/
> local/pgsql/data/postgresql.conf": No such file or directory
>
> The file does exist
> ls data
> PG_VERSION global pg_hba.conf pg_multixact pg_subtrans
> pg_twophase postgresql.conf
> base pg_clog pg_ident.conf pg_stat_tmp pg_tblspc pg_xlog
> postmaster.opts

Also, when attempting to unzip some src files, including the one I got
from this site I get this:

tar -zxvf postgresql-8.4.1.tar.gz
tar: Unrecognized archive format: Inappropriate file type or format
tar: Error exit delayed from previous errors.

THis is very strange to me!

The file I'm using came from source forge.

Any hints about this installation is greatly appreciated.

Don Fox

P.S. The app that will using postgresql is written in python.